A chafer is a portable food or beverage warmer or heater which includes a chafing dish for holding foods or beverages and a shelf disposed below the chafing dish for supporting at least one heater for warming the foods or beverages. Chafers are used to provide food service in restaurants, dining rooms, hotels, institutions and the like, and are often used to provide buffet service. Different types of chafing dishes exist, such as food trays, water pans, coffee urns and soup servers. A full line of chafers is made, for example, by the Vollrath Company of Wisconsin.
Chafers typically require one or two chafer heaters, depending upon the capacity of the chafing dish. Chafer heaters are typically metal canisters (i.e., cans) filled with a flammable chemical fuel. A standard can heater of this type is the "STERNO" can heater, with a diameter of approximately 3.5 inches. Accordingly, chafers typically include a shelf configured to support one or two standard can heaters such that heat from the burning chemical fuel is directed onto the bottom of a chafing dish. The shelf often has an aperture (e.g., a hole or recess) sized for receiving a standard can heater. The shelf and chafing dish are separated by a leg assembly to provide clearance for the can heater and the flames. Many chafers designed to accept chafer heaters of the type described above have been manufactured and sold.
Flammable fuel chafer heaters, however, suffer from a number of drawbacks such as being relatively expensive and having poor temperature control. Flammable fuel chafer heaters also emit relatively high levels of smoke, pollution and odor, especially when used indoors, and are inconvenient to use because of the difficulty in determining when the fuel will burn out.
Several attempts have been made to provide chafer heaters without the above-listed drawbacks. For example, one portable food warming device includes a gas burner assembly and a control box for controlling the supply of gas from a fuel cartridge to the gas burner. This device, however, does not adequately solve the above-listed problems and, in addition, is relatively bulky and inconvenient.
For another example, some chafers are equipped with electric resistance heaters integral to the chafing dish. For example, The Vollrath Company manufactures electric chafers having integral electric heaters for use in areas where fuel cans are not allowed or desired. The electric heaters provide an efficient and reliable source of heat without the odor, smoke and pollution problems associated with flammable-fuel chafer heaters. However, electric heaters integrally attached to chafing dishes cannot be used by chafers designed to use can heaters.
The Electric Heating Unit made by Host Products of California can be used as a heat source by some chafers. Many chafers, however, cannot use the Host Products unit since its cylindrical body has a diameter different than that of a standard can heater and, thus, the unit will not fit within apertures sized to receive standard can heaters. Further, the heat from the Host Products unit is difficult to control since it has only a single power setting (i.e., on/off). In addition, the Host Products unit does not include ballast weight to lower the center of gravity and provide a stable heat source. Other electric heaters, similar to the Host Products unit such as the Yukima model CW-240, the Sanyo model RNW-300, and another heating unit believed to be made in Japan, are also not configured to be received within apertures sized for standard can heaters, have only a single power setting, and do not include a ballast.
Accordingly, it would be advantageous to provide an improved chafer heater which uses an electrical heating assembly. It would further be advantageous to provide an electric chafer heater having variable power settings such as low and high-power settings. It would also be advantageous to provide a universal electric chafer heater configured for use by a high percentage of chafers. It would also be advantageous to provide an electric chafer heater with a ballast for increased stability, and a switch assembly for cutting off the flow of electricity to the heating assembly under predetermined conditions. Further, it would be advantageous to provide an electric chafer heater which provides an indication when the heating surface reaches a predetermined temperature.